Objectives: To evaluate in early and late preeclampsia a correlation of maternal venous Doppler flow characteristics with biochemical parameters in maternal serum and urine, or with gestational outcome. Study design: In this observational cross-sectional study, renal interlobar vein impedance index (RIVI) was measured according to a standardised protocol for combined electrocardiogram-Doppler ultrasonography in 86 women with uncomplicated pregnancy, 78 women with late onset preeclampsia (>= 34 w) and 67 with early onset preeclampsia (<34 w). For each group, maternal age, pre-gestational BMI and parity were recorded together with birth weight and percentile. For both early onset and late onset preeclampsia, maternal serum was analysed for thrombocyte count and concentrations of creatinine, ASAT, ALAT and uric acid and 24 h urine collections were analysed for creatinine clearance and proteinuria (mg/24 h). A non-parametric Mann Whitney U-tests was performed for continuous data and a Fisher's exact tests for categorical data. Significant linear dependence between variables was identified using Pearson's correlation coefficient at nominal level a = 0.05. Results: Proteinuria was higher in early onset than in late onset preeclampsia (1756 mg [838-6116 mg] versus 877 mg [416-1696 mg], p < 0.001), and this was also true for RIVI in both left (0.45 [0.40-0.55] versus 0.41 [0.35-0.45], p = 0.001) and right kidney (0.45 [0.39-0.55] versus 0.38 [0.30-0.43],p < 0.001). In our data set, there was a significant correlation between proteinuria and RIVI of left (correlation coefficient = 0.172, p = 0.036) and right kidney (correlation coefficient = 0.218, p = 0.009) in late onset but not early onset preeclampsia. Conclusion: Maternal RIVI may correlate with proteinuria of late onset preeclampsia. (C) 2014 Elsevier Ireland Ltd. All rights reserved.